URL masking / Stealth Redirection

I want to do URL Masking means that the visitors to the domain name will be forwarded to destination website, however the URL in their browser address bar will remain the same. Also known as Stealth Redirection or URL Hiding, this will ensure that your visitors see the orignal domain name and not the destination URL
For eg If your website is hosted at http://www.megrihost.com/Virtual_Pr...ps_servers.html. You choose to forward it to
"http://www.megrisoft.com/services/ ...private_server/ . Then if you enable URL Masking, your visitors will never see http://www.megrihost.com/Virtual_Pr...ps_servers.html as a URL in their browser address bar."

I've redirected from cPanel redirection but it shows destination url in address bar not Source URL.. & I do not want that please find below redirection rule for the same.

URL Masking / Stealth Redirection / URL Hiding

it can be done from Domain Control Panel. its called domain forwarding. i have done for other client & it works , but this case is very strange, this client is also want to use Mail Service, so if i use domain forwarding from domain control panel, then IP address would be changed.

testdomains.com is hosted on server "A" IP is 65.9x.xx.xxx

and i want to redirect this domain server "B"www.example.com/Test Domains/
which is different server.

after domain forwarding IP address for this domain would be changed like testdomains.com ip is 89.7x.xxx.xx

We can't use MX on server 'A' any idea guys ?

How does URL Masking work?
In case of URL Masking the Domain Forwarding server sends the client a Frames page where the Frame Source contains the destination URL you have specified. This ensures that the URL in the address bar of the browser does not change though the client sees the destination page.

Enabling URL masking will ensure that your visitors see the source URL and not the destination URL.

Enabling URL masking will serve a 'Frames' page to the browser. You may want to set an alternate <NOFRAMES> page content for search engines. Enter your HTML within <NOFRAMES></NOFRAMES> tags in the 'No Frames Page Content' box to set alternate page content.